1. Field of the Invention
The present invention relates to a self-movable vehicle, and more particularly to a self-movable vehicle, wherein the two rear frames are pivoted and moved outward and inward synchronously with an equal deflection angle by the design of the two meshing arcuate toothed plates, thereby enhancing the balance effect and stability of the self-movable vehicle.
2. Description of the Related Art
A conventional self-movable vehicle in accordance with the prior art shown in FIG. 7 comprises a head board 30, a handlebar 35 pivotally mounted on a front end of the head board 30, two rear frames 31 each having a front end pivotally mounted on a rear end of the head board 30 and a second end provided with a wheel seat 32 which has a bottom provided with a rear wheel set 33, and two tread boards 34 each mounted on a respective one of the two rear frames 31.
In operation, the user""s two feet are stepped on the two tread boards 34, so that the two rear frames 31 are initially pivoted and moved outward relative to each other, and are then pivoted and moved toward each other, so that the two rear wheel sets 33 are deflected, thereby driving the self-movable vehicle to move forward.
However, each of the two tread boards 34 is fixed on a respective one of the two rear frames 31, so that when the two rear frames 31 are pivoted and moved outward, the two tread boards 34 are also moved outward, thereby producing an angular displacement, so that the user""s ankles are easily twisted and distorted, thereby injuring the user""s ankles. In addition, the user has to apply a larger stepping force to move the self-movable vehicle, thereby consuming energy and manual work.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional self-movable vehicle.
The primary objective of the present invention is to provide a self-movable vehicle, wherein the two rear frames are pivoted and moved outward and inward synchronously with an equal deflection angle by the design of the two meshing arcuate toothed plates, thereby enhancing the balance effect and stability of the self-movable vehicle.
Another objective of the present invention is to provide a self-movable vehicle, wherein the tensile spring mounted between the two rear frames may help the two rear frames to approach each other easily and conveniently, thereby facilitating the user pivoting and moving the two rear frames to move the self-movable vehicle, and thereby saving the manual work.
A further objective of the present invention is to provide a self-movable vehicle, wherein the bent portion of the pivot plate is slidably mounted in the arcuate slot of each of the two rear frames, thereby limiting further rotation of each of the two tread boards and each of the two rear wheel sets.
In accordance with the present invention, there is provided a self-movable vehicle, comprising a head board, a head tube secured on a front end of the head board, a steering tube pivotally mounted on the head tube and having a lower end provided with a front wheel, two rear frames each having a front end pivotally mounted on a rear end of the head board, two tread boards each pivotally mounted on a top face of a rear end of a respective one of the two rear frames, and two rear wheel sets each pivotally mounted on a bottom face of the rear end of a respective one of the two rear frames, wherein:
the self-movable vehicle further comprises two arcuate toothed plates meshing with each other and each secured on the front end of a respective one of the two rear frames to pivot therewith, and a tensile spring mounted between the two rear frames; and
each of the two rear frames has a bottom face formed with an arcuate slot, each of the two tread boards has a bottom face protruded with a shaft extended through each of the two rear frames, a pivot plate is secured on the shaft of each of the two tread boards, the pivot plate has a first side formed with a bent portion slidably mounted in the arcuate slot of each of the two rear frames and a second side secured with two linking members each having a free end formed with a bent end which is secured on each of the two rear wheel sets.